Oscillator, audio transmission chip and electronic equipment
By introducing an adjustable current temperature coefficient circuit structure into the ring oscillator of the vehicle audio transmission chip, the oscillator delay is controlled by using the negative temperature coefficient and the zero-temperature drift current module, the instability of the oscillation frequency in the process angle deviation is solved, and the frequency stable output within the chip area is achieved.
Patent Information
- Application Number
- CN202510126685.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-27
- Publication Date
- 2025-05-13
AI Technical Summary
In the case of process angle deviation of the oscillator in the existing vehicle audio transmission chip, the oscillator frequency changes greatly, making it difficult to achieve stable frequency output within a smaller chip area.
Based on the ring oscillator, a circuit structure with adjustable current temperature coefficient is designed. Through the negative temperature coefficient current generation module and the zero temperature drift current generation module, the ring oscillator delay is controlled to realize the adjustment and compensation of the oscillation frequency.
It realizes a stable output of the oscillation frequency within a smaller chip area, and under the process angle deviation, the frequency change is controlled within plus or minus 5%, improving the frequency stability and adaptability of the oscillator.
Smart Images
Figure CN119995522A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor chips, and in particular to an oscillator, an audio transmission chip and an electronic device. Background Art
[0002] Car audio transmission chips usually use mixed analog and digital chips, including digital circuits and analog circuits. The internal analog circuit needs to generate a 50Mhz oscillation frequency and provide it to the digital circuit as a digital working clock. The traditional oscillator (OSC) structure in the audio transmission chip includes a ring oscillator and an LC oscillator. The prior art usually uses an ordinary ring oscillator composed of logic gates, which has a small area but a large output frequency deviation with the process angle, with a maximum deviation of up to plus or minus 40%. Alternatively, an LC oscillator is used, and the output frequency deviation with the process angle is relatively small, but the inductor occupies a very large chip area. Summary of the invention
[0003] In view of the above-mentioned defects or deficiencies in the prior art, the present invention provides an oscillator, an audio transmission chip and an electronic device, designs a circuit structure with an adjustable current temperature coefficient based on a ring oscillator, controls the delay of the ring oscillator, and achieves an oscillation frequency deviation of about plus or minus 5% with the process angle in a smaller chip area.
[0004] In a first aspect, the present invention provides an oscillator, comprising: A negative temperature coefficient current generating module, a zero temperature drift current generating module and an oscillation generating module; The first end of the negative temperature coefficient current generating module is connected to a reference voltage, and the second end outputs an adjustable negative temperature coefficient current. The first end of the zero temperature drift current generating module is connected to a reference current, and the second end outputs an adjustable zero temperature drift current. The second end of the negative temperature coefficient current generating module is connected to the second end of the zero temperature drift current generating module and the first end of the oscillation generating module. The first end of the oscillation generating module is connected to a positive temperature coefficient current, and the second end outputs an oscillation signal. The positive temperature coefficient current is obtained by subtracting the negative temperature coefficient current from the zero temperature drift current.
[0005] Furthermore, it also includes: the oscillator is configured to reduce the negative temperature coefficient current and increase the zero temperature drift current, so that the positive temperature coefficient decreases while the positive temperature coefficient current remains unchanged; increase the negative temperature coefficient current and reduce the zero temperature drift current, so that the positive temperature coefficient increases while the positive temperature coefficient current remains unchanged.
[0006] Further, the negative temperature coefficient current generating module includes an amplifier, a first resistor, a first PMOS tube, a second PMOS tube, a first NMOS tube, a second NMOS tube, a third NMOS tube, a fourth NMOS tube, a fifth NMOS tube, a sixth NMOS tube, a seventh NMOS tube, a first switch, a second switch, a third switch and a fourth switch; The first end of the amplifier is connected to a reference voltage, the second end is connected to the first end of the first resistor and the third end of the first NMOS tube, the second end of the first resistor is grounded, the third end of the amplifier is connected to the second end of the first NMOS tube, the first end of the first NMOS tube is connected to the third end, the second end of the first PMOS tube and the second end of the second PMOS tube, the first end of the first PMOS tube is connected to a power supply, the first end of the second PMOS tube is connected to a power supply, the third end of the second PMOS tube is connected to the first ends of the first switch, the second switch, the third switch and the fourth switch, and is also connected to the first end and the second end of the second NMOS tube, the second NMOS tube is connected to the second end of the third NMOS tube, the first ends of the third NMOS tube, the fourth NMOS tube, the fifth NMOS tube, the sixth NMOS tube and the seventh NMOS tube are all connected to each other and serve as the output end of the negative temperature coefficient current, and the third ends are all connected to the third end of the second NMOS tube and grounded, the second end of the fourth NMOS tube is connected to the second end of the fourth switch, the second end of the fifth NMOS tube is connected to the second end of the third switch, the second end of the sixth NMOS tube is connected to the second end of the second switch, and the second end of the seventh NMOS tube is connected to the second end of the first switch.
[0007] Further, the zero temperature drift current generating module includes an eighth NMOS tube, a ninth NMOS tube, a tenth NMOS tube, an eleventh NMOS tube, a twelfth NMOS tube, a thirteenth NMOS tube, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a third PMOS tube, a fourth PMOS tube, a fifth PMOS tube, a sixth PMOS tube, a seventh PMOS tube, an eighth PMOS tube, a ninth switch, a tenth switch, an eleventh switch and a twelfth switch; The first end of the eighth NMOS tube is connected to the reference current and connected to the first ends of the fifth switch, the sixth switch, the seventh switch, and the eighth switch, and is also connected to the second end of the eighth NMOS tube and the second end of the ninth NMOS tube. The first ends of the ninth NMOS tube, the tenth NMOS tube, the eleventh NMOS tube, the twelfth NMOS tube, and the thirteenth NMOS tube are all connected to each other, and the third ends are all connected to the third end of the eighth NMOS tube and grounded. The second end of the eighth switch is connected to the second end of the tenth NMOS tube, the second end of the seventh switch is connected to the second end of the eleventh NMOS tube, the second end of the sixth switch is connected to the second end of the twelfth NMOS tube, the second end of the fifth switch is connected to the second end of the thirteenth NMOS tube, and the second end of the thirteenth NMOS tube is connected to the second end of the 13th NMOS tube. One end is connected to the third end, the second end and the first ends of the ninth switch, the tenth switch, the eleventh switch and the twelfth switch of the third PMOS tube, the second end of the third PMOS tube is connected to the second end of the fourth PMOS tube, the first ends of the fourth PMOS tube, the fifth PMOS tube, the sixth PMOS tube, the seventh PMOS tube and the eighth PMOS tube are all connected to the first end of the third PMOS tube and connected to the power supply, and the third ends are all connected to each other and serve as the output end of the zero temperature drift current, the second end of the twelfth switch is connected to the second end of the fifth PMOS tube, the second end of the eleventh switch is connected to the second end of the sixth PMOS tube, the second end of the tenth switch is connected to the second end of the seventh PMOS tube, and the second end of the ninth switch is connected to the second end of the eighth PMOS tube.
[0008] Further, the oscillation generation module includes a fourteenth NMOS tube, a delay unit with the same three-stage structure, and an AND gate; The first end of the fourteenth NMOS tube is connected to the positive temperature coefficient current, the second end is short-circuited with the first end and connected to the third end of the three-stage delay unit, the first ends of the three-stage delay units are all connected to the power supply, the fourth ends are all connected to the third end of the fourteenth NMOS tube and grounded, the second end of the first-stage delay unit is connected to the third end of the AND gate and serves as an oscillation signal output end, the fifth end of the first-stage delay unit is connected to the second end of the second-stage delay unit, the fifth end of the second-stage delay unit is connected to the second end of the third-stage delay unit, the fifth end of the third-stage delay unit is connected to the first end of the AND gate, and the second end of the AND gate is connected to the reset signal.
[0009] Further, the delay unit includes a ninth PMOS tube, a tenth PMOS tube, an eleventh PMOS tube, a fifteenth NMOS tube, a sixteenth NMOS tube, a seventeenth NMOS tube and an eighteenth NMOS tube; The first ends of the ninth PMOS tube, the tenth PMOS tube, and the eleventh PMOS tube are connected to each other as the first end of the delay unit, the second end of the ninth PMOS tube is connected to the second end of the sixteenth NMOS tube as the second end of the delay unit, the third end of the ninth PMOS tube is connected to the first end of the sixteenth NMOS tube and connected to the second end of the tenth PMOS tube and the second end of the seventeenth NMOS tube, the third end of the sixteenth NMOS tube is connected to the first end of the fifteenth NMOS tube, the second end of the fifteenth NMOS tube serves as the third end of the delay unit, the third end of the fifteenth NMOS tube serves as the fourth end of the delay unit, the third end of the tenth PMOS tube is connected to the first end of the seventeenth NMOS tube and connected to the second end of the eleventh PMOS tube and the second end of the eighteenth NMOS tube, the third end of the seventeenth NMOS tube is grounded, the third end of the eleventh PMOS tube is connected to the first end of the eighteenth NMOS tube and serves as the fifth end of the delay unit, and the third end of the eighteenth NMOS tube is grounded; Furthermore, it also includes that when the second-end input of the ninth PMOS tube and the sixteenth NMOS tube is switched from a low level to a high level, the sixteenth NMOS tube is turned on, and the second ends of the tenth PMOS tube and the seventeenth NMOS tube are discharged to the ground through the sixteenth NMOS tube and the fifteenth NMOS tube, and are discharged from a high level to a low level; when the second-end input of the ninth PMOS tube and the sixteenth NMOS tube is switched from a high level to a low level, the ninth PMOS tube is turned on, and the second ends of the tenth PMOS tube and the seventeenth NMOS tube charge the power supply through the ninth PMOS tube, and are charged from a low level to a high level.
[0010] Furthermore, the first end of the NMOS tube is the drain of the NMOS tube, the second end is the gate of the NMOS tube, and the third end is the source of the NMOS tube; the first end of the PMOS tube is the source of the PMOS tube, the second end is the gate of the PMOS tube, and the third end is the drain of the PMOS tube.
[0011] In a second aspect, the present invention provides an audio transmission chip, comprising any one of the oscillators described above.
[0012] In a third aspect, the present invention provides an electronic device, comprising the audio transmission chip.
[0013] An oscillator, an audio transmission chip and an electronic device provided by the present invention generate adjustable negative temperature coefficient current and zero temperature drift current by adding current branches on the basis of a ring oscillator structure: a negative temperature coefficient current generating module and a zero temperature drift current generating module, thereby obtaining an adjustable positive temperature coefficient current. By adjusting the current size of the current branch and the positive temperature coefficient of the current, the output frequency of the oscillator oscillation signal can be adjusted, and the variation of the output frequency of the oscillation signal with temperature can be compensated, thereby achieving a smaller chip area and an oscillation signal output frequency with smaller process angle deviation. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 is a structural diagram of an oscillator provided by an embodiment of the present application; Figure 2 This is a circuit diagram of a negative temperature coefficient current generating module of an oscillator provided by an embodiment of the present application; Figure 3 This is a negative temperature coefficient current waveform diagram of an oscillator provided by an embodiment of the present application; Figure 4 This is a circuit diagram of a zero temperature drift current generating module of an oscillator provided by an embodiment of the present application; Figure 5 This is a zero temperature drift current waveform diagram of an oscillator provided by an embodiment of the present application; Figure 6 It is a circuit diagram of an oscillation generating module of an oscillator provided by one embodiment of the present application; Figure 7 This is a positive temperature coefficient current waveform diagram of an oscillator provided by an embodiment of the present application; Figure 8 This is a simulation result diagram of the variation range of the oscillation frequency of an oscillator with the process angle provided by an embodiment of the present application; Fig. 9 This is a structural block diagram of an audio transmission chip provided by an embodiment of the present application; Fig.10 It is a structural block diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION
[0015] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0016] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.
[0017] It should be understood that although the terms first, second, third, etc. may be used to describe the acquisition modules in the embodiments of the present invention, the acquisition modules should not be limited to these terms. These terms are only used to distinguish the acquisition modules from each other.
[0018] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.
[0019] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is formed "on" or "under" another element, it can not only be formed directly "on" or "under" another element, but also be formed "on" or "under" another element indirectly through an intermediate element.
[0020] refer to Figure 1 , an embodiment of the present invention provides an oscillator 1, the oscillator 1 comprising: A negative temperature coefficient current generating module 11, a zero temperature drift current generating module 12 and an oscillation generating module 13; The first end of the negative temperature coefficient current generating module 11 is connected to the reference voltage Vbias, and the second end outputs an adjustable negative temperature coefficient current Ictat. The first end of the zero temperature drift current generating module 12 is connected to the reference current I25u, and the second end outputs an adjustable zero temperature drift current Ibias. The second end of the negative temperature coefficient current Ictat generating module 11 is connected to the second end of the zero temperature drift current generating module 12 and the first end of the oscillation generating module 13. The first end of the oscillation generating module 13 is connected to the positive temperature coefficient current Iptat, and the second end outputs an oscillation signal, wherein the positive temperature coefficient current Iptat is obtained by subtracting the negative temperature coefficient current Ictat from the zero temperature drift current Ibias.
[0021] The following describes the structure of each component module of an oscillator 1 provided by an embodiment of the present invention.
[0022] Exemplary, reference Figure 2 The negative temperature coefficient current generating module 11 includes but is not limited to: an amplifier AMP, a resistor R1, a PMOS tube MP1, a PMOS tube MP2, an NMOS tube MN1, an NMOS tube MN2, an NMOS tube MN3, an NMOS tube MN4, an NMOS tube MN5, an NMOS tube MN6, an NMOS tube MN7, a switch S1, a switch S2, a switch S3 and a switch S4; The first end of the amplifier AMP is connected to the reference voltage Vbias, the second end is connected to the first end of the resistor R1 and the source of the NMOS tube MN1, the second end of the resistor R1 is grounded, the third end of the amplifier AMP is connected to the gate of the NMOS tube MN1, the drain of the NMOS tube MN1 is connected to the drain and gate of the PMOS tube MP1 and the gate of the PMOS tube MP2, the source of the PMOS tube MP1 is connected to the power supply VDD, the source of the PMOS tube MP2 is connected to the power supply VDD, the drain of the PMOS tube MP2 is connected to the first end of the switch S1, the switch S2, the switch S3 and the switch S4, and is also connected to the The drain and gate of the NMOS tube MN2 are connected to the gate of the NMOS tube MN3. The drains of the NMOS tubes MN3, MN4, MN5, MN6 and MN7 are all connected to each other and serve as the output end of the negative temperature coefficient current Ictat. The sources are all connected to the source of the NMOS tube MN2 and grounded. The gate of the NMOS tube MN4 is connected to the second end of the switch S4, the gate of the NMOS tube MN5 is connected to the second end of the switch S3, the gate of the NMOS tube MN6 is connected to the second end of the switch S2, and the gate of the NMOS tube MN7 is connected to the second end of the switch S1.
[0023] Preferably, the embodiment of the present invention selects the resistor R1=25KΩ of the negative temperature coefficient current generating module 11, and the width-to-length ratios of the MOS tubes are as follows: the PMOS tubes MP1 and MP2 are 4u / 1u (um, micrometers), the NMOS tube MN1 is 8u / 0.5u, MN2 is 5u / 2u, MN3 is 0.5u / 2u, MN4 is 4u / 2u, MN5 is 2u / 2u, MN6 is 1u / 2u, and MN7 is 0.5u / 2u. The voltage of resistor R1 is clamped to the reference voltage Vbias=0.6V through amplifier AMP, and the current flowing through NMOS tube MN1 is Vbias / R1, and the current is mirrored to MN2 through MP1 and MP2, and MN2 is mirrored to MN3-MN7 through the adjustable MOS tube. Since the resistance value of resistor R1 increases with the increase of temperature, the output adjustable current decreases with the increase of temperature, thereby obtaining an adjustable negative temperature coefficient current Ictat. The size of negative temperature coefficient current Ictat is adjusted by configuring switches S1-S4. The waveform of the adjusted negative temperature coefficient current Ictat is as follows: Figure 3 shown.
[0024] Exemplary, reference Figure 4 The zero temperature drift current generating module 12 includes but is not limited to: NMOS tube MN8, NMOS tube MN9, NMOS tube MN10, NMOS tube MN11, NMOS tube MN12, NMOS tube MN13, switch S5, switch S6, switch S7, switch S8, PMOS tube MP3, PMOS tube MP4, PMOS tube MP5, PMOS tube MP6, PMOS tube MP7, PMOS tube MP8, switch S9, switch S10, switch S11 and switch S12; The drain of the NMOS tube MN8 is connected to the reference current I25u and connected to the first ends of the switches S5, S6, S7 and S8, and is also connected to the gate of the NMOS tube MN8 and the gate of the NMOS tube MN9. The drains of the NMOS tubes MN9, MN10, MN11, MN12 and MN13 are all connected to each other, and their sources are all connected to the source of the NMOS tube MN8 and grounded. The second end of the switch S8 is connected to the gate of the NMOS tube MN10, the second end of the switch S7 is connected to the gate of the NMOS tube MN11, the second end of the switch S6 is connected to the gate of the NMOS tube MN12, the second end of the switch S5 is connected to the gate of the NMOS tube MN13, and the second end of the NMOS tube MN13 is connected to the gate of the NMOS tube MN14. The drain of the PMOS tube MP3 is connected to the drain, gate and first ends of switches S9, S10, S11 and S12. The gate of the PMOS tube MP3 is connected to the gate of the PMOS tube MP4. The sources of the PMOS tube MP4, PMOS tube MP5, PMOS tube MP6, PMOS tube MP7 and PMOS tube MP8 are all connected to the source of the PMOS tube MP3 and to the power supply VDD. The drains are all connected to each other and serve as the output end of the zero temperature drift current Ibias. The second end of the switch S12 is connected to the gate of the PMOS tube MP5. The second end of the switch S11 is connected to the gate of the PMOS tube MP6. The second end of the switch S10 is connected to the gate of the PMOS tube MP7. The second end of the switch S9 is connected to the gate of the PMOS tube MP8.
[0025] Preferably, the embodiment of the present invention selects the following MOS tube width-to-length ratios for the zero temperature drift current generating module 12: NMOS tube MN8 is 16u / 2u, MN9 is 4u / 2u, MN10 is 4u / 2u, MN11 is 2u / 2u, MN12 is 1u / 2u, MN13 is 0.5u / 2u, PMOS tube MP3 is 10u / 1u, MP4 is 9u / 1u, MP5 is 8u / 1u, MP6 is 4u / 1u, MP7 is 2u / 1u, MP8 is 1u / 1u. The current I25u is mirrored to MN9-MN13 through MN8, and the current size is adjusted by switches S5-S8, and then the current is mirrored to MP4-MP8 by MP3, and the current size is adjusted by switches S9-S12, thereby obtaining an adjustable zero temperature drift current Ibias. The waveform of the adjusted zero temperature drift current Ibias is shown in FIG. Figure 5 shown.
[0026] Exemplary, reference Figure 6 , the oscillation generation module 13 includes but is not limited to: NMOS tube MN14, three-stage delay unit with the same structure and AND gate AND1; Among them, the drain of the NMOS tube MN14 is connected to the positive temperature coefficient current Iptat, the gate and the drain are short-circuited and connected to the third end of the three-stage delay unit, the first ends of the three-stage delay units are connected to the power supply VDD, the fourth ends are connected to the source of the NMOS tube MN14 and grounded, the second end of the delay unit 131 is connected to the third end of the AND gate AND1 and serves as the oscillation signal output end, the fifth end of the delay unit 131 is connected to the second end of the delay unit 132, the fifth end of the delay unit 132 is connected to the second end of the delay unit 133, the fifth end of the delay unit 133 is connected to the first end of the AND gate AND1, and the second end of the AND gate AND1 is connected to the reset signal Rstb.
[0027] Specifically, each stage of delay units includes but is not limited to: PMOS tube MP9, PMOS tube MP10, PMOS tube MP11, NMOS tube MN15, NMOS tube MN16, NMOS tube MN17 and NMOS tube MN18; Among them, the sources of the PMOS tubes MP9, MP10, and MP11 are connected to serve as the first end of the delay unit, the gate of the PMOS tube MP9 is connected to the gate of the NMOS tube MN16 to serve as the second end of the delay unit, the drain of the PMOS tube MP9 is connected to the drain of the NMOS tube MN16 and connected to the gate of the PMOS tube MP10 and the gate of the NMOS tube MN17, the source of the NMOS tube MN16 is connected to the drain of the NMOS tube MN15, the gate of the NMOS tube MN15 serves as the third end of the delay unit, the source of the NMOS tube MN15 serves as the fourth end of the delay unit, the drain of the PMOS tube MP10 is connected to the drain of the NMOS tube MN17 and connected to the gate of the PMOS tube MP11 and the gate of the NMOS tube MN18, the source of the NMOS tube MN17 is grounded, the drain of the PMOS tube MP11 is connected to the drain of the NMOS tube MN18 and serves as the fifth end of the delay unit, and the source of the NMOS tube MN18 is grounded.
[0028] Preferably, the MOS tube width-to-length ratio of the oscillation generating module 13 selected in the embodiment of the present invention is as follows: NMOS tube MN14 is 4u / 2u, MN15 is 8u / 2u, MN16 is 1.36u / 0.25u, MN17 is 0.68u / 4u, MN18 is 0.68u / 0.3u, PMOS tube MP9 is 3.6u / 0.25u, MP10 is 1.8u / 4u, MP11 is 1.8u / 0.3u, and the three-stage delay unit structure and the MOS tube have the same width-to-length ratio. The zero temperature drift current Ibias minus the negative temperature coefficient current Ictat obtains the positive temperature coefficient current Iptat and provides it to MN14. The magnitude of the Iptat current is determined by simulation. After the magnitude of the Iptat current is determined, switches S1-S4 and S9-S12 are adjusted simultaneously. In this embodiment, under the TYP (typical, typical process) condition, that is, the TT process angle, the temperature is 45°C, and the voltage is 1.8V, the negative temperature coefficient current Ictat is reduced and the zero temperature drift current Ibias is increased, so that the positive temperature coefficient of the positive temperature coefficient current Iptat remains unchanged. By increasing the negative temperature coefficient current Ictat and reducing the zero temperature drift current Ibias, the positive temperature coefficient of the positive temperature coefficient current Iptat remains unchanged. In this way, the positive temperature coefficient of the current can be adjusted under the same current magnitude. The waveform of the positive temperature coefficient current Iptat is as follows: Figure 7 As shown;
[0029] In the delay unit, the inverter load composed of the PMOS tube MP9 and the NMOS tube MN16 is an inverter composed of MP10 and MN17. In this embodiment, the channel length of MP10 and MN17 is 4u. The larger the channel length, the larger the equivalent load capacitance. When the gate input of MP9 and MN16 is switched from a low level to a high level, MN16 is turned on, and the gates of MP10 and MN17 are discharged to the ground through MN16 and MN15, from a high level to a low level. The discharge current is Iptat*2. It can be seen from the capacitor discharge formula that the discharge time t= (C*VDD) / 2*Iptat, C is the capacitance; when the gate input of MP9 and MN16 is switched from high level to low level, MP9 is turned on, and the gates of MP10 and MN17 charge the power supply VDD through MP9, from low level to high level. Since the on-resistance of MP10 is small, the charging time is much shorter than the discharge time t, and the oscillation clock period of the oscillator is mainly determined by the discharge time t. By adjusting the positive temperature coefficient of current, the load capacitance change caused by temperature change can be compensated, and the deviation of the oscillation frequency of the oscillator with temperature change can be optimized.
[0030] Ideally, the oscillator generates an oscillation frequency of 50Mhz. An oscillator 1 provided in an embodiment of the present invention is referred to as Figure 8The simulation result diagram of the oscillator oscillation frequency changing with the process angle shows that through adjustment, the deviation of the oscillation frequency changing with the process angle (TT, FF, SS, FS, SF), temperature (-40C, 45C, 130C) and power supply (1.62V, 1.8V, 1.98V) is within plus or minus 5%. The circuit structure of the oscillator proposed in the present invention can achieve a relatively small module area and an oscillation frequency with smaller deviation with the process angle.
[0031] An oscillator provided by an embodiment of the present invention generates an adjustable negative temperature coefficient current and a zero temperature drift current by adding current branches on the basis of a ring oscillator structure: a negative temperature coefficient current generating module and a zero temperature drift current generating module, thereby obtaining an adjustable positive temperature coefficient current. By adjusting the current size of the current branch and the positive temperature coefficient of the current, the oscillation frequency of the oscillator can be adjusted, and the variation of the oscillation frequency with temperature can be compensated, thereby achieving a smaller chip area and an oscillation frequency with smaller process angle deviation.
[0032] The embodiment of the present invention also provides an audio transmission chip 2, such as Fig. 9 As shown, the audio transmission chip 2 includes but is not limited to Figure 1 Corresponding to the oscillator 1 in the embodiment.
[0033] The embodiment of the present invention further provides an electronic device 3, such as Fig.10 As shown, the electronic device 3 includes but is not limited to Fig. 9 The audio transmission chip 2 in the corresponding embodiment.
[0034] The above description is only a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of disclosure involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but also should cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) to form a technical solution.
Claims
1. An oscillator, characterized in that: include: A negative temperature coefficient current generating module, a zero temperature drift current generating module and an oscillation generating module; The first end of the negative temperature coefficient current generating module is connected to a reference voltage, and the second end outputs an adjustable negative temperature coefficient current. The first end of the zero temperature drift current generating module is connected to a reference current, and the second end outputs an adjustable zero temperature drift current. The second end of the negative temperature coefficient current generating module is connected to the second end of the zero temperature drift current generating module and the first end of the oscillation generating module. The first end of the oscillation generating module is connected to a positive temperature coefficient current, and the second end outputs an oscillation signal. The positive temperature coefficient current is obtained by subtracting the negative temperature coefficient current from the zero temperature drift current.
2. An oscillator according to claim 1, characterized in that: Also includes: The oscillator is configured to reduce the negative temperature coefficient current and increase the zero temperature drift current, so that the positive temperature coefficient decreases while the positive temperature coefficient current remains unchanged; and to increase the negative temperature coefficient current and reduce the zero temperature drift current, so that the positive temperature coefficient increases while the positive temperature coefficient current remains unchanged.
3. An oscillator according to claim 1, characterized in that: The negative temperature coefficient current generating module includes an amplifier, a first resistor, a first PMOS tube, a second PMOS tube, a first NMOS tube, a second NMOS tube, a third NMOS tube, a fourth NMOS tube, a fifth NMOS tube, a sixth NMOS tube, a seventh NMOS tube, a first switch, a second switch, a third switch and a fourth switch; The first end of the amplifier is connected to a reference voltage, the second end is connected to the first end of the first resistor and the third end of the first NMOS tube, the second end of the first resistor is grounded, the third end of the amplifier is connected to the second end of the first NMOS tube, the first end of the first NMOS tube is connected to the third end, the second end of the first PMOS tube and the second end of the second PMOS tube, the first end of the first PMOS tube is connected to a power supply, the first end of the second PMOS tube is connected to a power supply, the third end of the second PMOS tube is connected to the first ends of the first switch, the second switch, the third switch and the fourth switch, and is also connected to the first end and the second end of the second NMOS tube, the second NMOS tube is connected to the second end of the third NMOS tube, the first ends of the third NMOS tube, the fourth NMOS tube, the fifth NMOS tube, the sixth NMOS tube and the seventh NMOS tube are all connected to each other and serve as the output end of the negative temperature coefficient current, and the third ends are all connected to the third end of the second NMOS tube and grounded, the second end of the fourth NMOS tube is connected to the second end of the fourth switch, the second end of the fifth NMOS tube is connected to the second end of the third switch, the second end of the sixth NMOS tube is connected to the second end of the second switch, and the second end of the seventh NMOS tube is connected to the second end of the first switch.
4. An oscillator according to claim 1, characterized in that: The zero temperature drift current generating module includes an eighth NMOS tube, a ninth NMOS tube, a tenth NMOS tube, an eleventh NMOS tube, a twelfth NMOS tube, a thirteenth NMOS tube, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a third PMOS tube, a fourth PMOS tube, a fifth PMOS tube, a sixth PMOS tube, a seventh PMOS tube, an eighth PMOS tube, a ninth switch, a tenth switch, an eleventh switch and a twelfth switch; The first end of the eighth NMOS tube is connected to the reference current and connected to the first ends of the fifth switch, the sixth switch, the seventh switch, and the eighth switch, and is also connected to the second end of the eighth NMOS tube and the second end of the ninth NMOS tube. The first ends of the ninth NMOS tube, the tenth NMOS tube, the eleventh NMOS tube, the twelfth NMOS tube, and the thirteenth NMOS tube are all connected to each other, and the third ends are all connected to the third end of the eighth NMOS tube and grounded. The second end of the eighth switch is connected to the second end of the tenth NMOS tube, the second end of the seventh switch is connected to the second end of the eleventh NMOS tube, the second end of the sixth switch is connected to the second end of the twelfth NMOS tube, the second end of the fifth switch is connected to the second end of the thirteenth NMOS tube, and the second end of the thirteenth NMOS tube is connected to the second end of the 13th NMOS tube. One end is connected to the third end, the second end and the first ends of the ninth switch, the tenth switch, the eleventh switch and the twelfth switch of the third PMOS tube, the second end of the third PMOS tube is connected to the second end of the fourth PMOS tube, the first ends of the fourth PMOS tube, the fifth PMOS tube, the sixth PMOS tube, the seventh PMOS tube and the eighth PMOS tube are all connected to the first end of the third PMOS tube and connected to the power supply, and the third ends are all connected to each other and serve as the output end of the zero temperature drift current, the second end of the twelfth switch is connected to the second end of the fifth PMOS tube, the second end of the eleventh switch is connected to the second end of the sixth PMOS tube, the second end of the tenth switch is connected to the second end of the seventh PMOS tube, and the second end of the ninth switch is connected to the second end of the eighth PMOS tube.
5. An oscillator according to claim 4, characterized in that: The oscillation generation module includes a fourteenth NMOS tube, a delay unit with three levels of the same structure, and an AND gate; The first end of the fourteenth NMOS tube is connected to the positive temperature coefficient current, the second end is short-circuited with the first end and connected to the third end of the three-stage delay unit, the first ends of the three-stage delay units are all connected to the power supply, the fourth ends are all connected to the third end of the fourteenth NMOS tube and grounded, the second end of the first-stage delay unit is connected to the third end of the AND gate and serves as an oscillation signal output end, the fifth end of the first-stage delay unit is connected to the second end of the second-stage delay unit, the fifth end of the second-stage delay unit is connected to the second end of the third-stage delay unit, the fifth end of the third-stage delay unit is connected to the first end of the AND gate, and the second end of the AND gate is connected to the reset signal.
6. An oscillator according to claim 5, characterized in that: The delay unit includes a ninth PMOS tube, a tenth PMOS tube, an eleventh PMOS tube, a fifteenth NMOS tube, a sixteenth NMOS tube, a seventeenth NMOS tube and an eighteenth NMOS tube; The first ends of the ninth PMOS tube, the tenth PMOS tube, and the eleventh PMOS tube are connected to serve as the first end of the delay unit. The second end of the ninth PMOS tube is connected to the second end of the sixteenth NMOS tube and serves as the second end of the delay unit. The third end of the ninth PMOS tube is connected to the first end of the sixteenth NMOS tube and the second end of the tenth PMOS tube and the second end of the seventeenth NMOS tube. The third end of the sixteenth NMOS tube is connected to the first end of the fifteenth NMOS tube. The second end of the fifteenth NMOS tube serves as the third end of the delay unit. The third end of the fifteenth NMOS tube serves as the fourth end of the delay unit. The third end of the tenth PMOS tube is connected to the first end of the seventeenth NMOS tube and the second end of the eleventh PMOS tube and the second end of the eighteenth NMOS tube. The third end of the seventeenth NMOS tube is grounded. The third end of the eleventh PMOS tube is connected to the first end of the eighteenth NMOS tube and serves as the fifth end of the delay unit. The third end of the eighteenth NMOS tube is grounded.
7. An oscillator according to claim 6, characterized in that: It also includes that when the second-end input of the ninth PMOS tube and the sixteenth NMOS tube is switched from a low level to a high level, the sixteenth NMOS tube is turned on, and the second ends of the tenth PMOS tube and the seventeenth NMOS tube are discharged to the ground through the sixteenth NMOS tube and the fifteenth NMOS tube, and are discharged from a high level to a low level; when the second-end input of the ninth PMOS tube and the sixteenth NMOS tube is switched from a high level to a low level, the ninth PMOS tube is turned on, and the second ends of the tenth PMOS tube and the seventeenth NMOS tube charge the power supply through the ninth PMOS tube, and are charged from a low level to a high level.
8. An oscillator according to any one of claims 3 to 7, characterized in that: The first end of the NMOS tube is the drain of the NMOS tube, the second end is the gate of the NMOS tube, and the third end is the source of the NMOS tube. The first end of the PMOS tube is the source of the PMOS tube, the second end is the gate of the PMOS tube, and the third end is the drain of the PMOS tube.
9. An audio transmission chip, characterized in that: The audio transmission chip comprises the oscillator according to any one of claims 1 to 8.
10. An electronic device, characterized in that: The electronic device comprises the audio transmission chip according to claim 9.